JPH07204870A - Marking method by laser beam - Google Patents

Abstract

PURPOSE:To realize the black marking excellent in the durability on the surface of a work. CONSTITUTION:A recessed part formed on the surface of a work 10 made of plastics is the heated and evaporated part of the part irradiated with the laser beam. The black carbonized layer 11 of the plastics is generated and left on the surface of the recessed part, and this carbonized layer 11 apparently becomes the black marking. This carbonized layer 11 is firmly adhered to the surface of the recessed part, and does not disappear even when the time is elapsed. Even when the surface of the work 10 is rubbed with other members, the carbonized layer 11 is in the part recessed from the surface of the work 10, and does not disappear. The other part than the black marked part becomes the color of the material of the work 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser marking method for marking a surface of a work with a highly durable black marking.

[0002]

2. Description of the Related Art Conventionally, most of markings such as letters, numbers and symbols on the surface of a work are made by a printing method. The printing method includes an inkjet method and a mask method. The inkjet method is a method in which ink is ejected from a nozzle to form a row of dots that are continuously arranged to form an apparent line. In the mask method, a hole is formed in a shape to be marked on a thin shielding plate, ink is sprayed, and the ink is attached to a portion corresponding to the hole.

[0003]

In the marking by the conventional printing method, the marked portion is initially clear, but when the marking surface rubs against another member, there is a drawback that the sharpness fades with time. In extreme cases, it may disappear. The problem to be solved by the present invention is to solve the above problems of the conventional technique and to provide a laser marking method for performing black marking on a work surface with excellent durability.

[0004]

According to a first aspect of the present invention, there is provided a laser marking method in which a surface of a plastic work is irradiated with laser light, and a carbonized layer of plastic is formed on a surface of a recess formed at the irradiation position. The remaining material is marked with an apparent black color.

A laser marking method according to a second aspect of the present invention irradiates a surface of a work coated with a mixture of fine plastic particles and a coating with a laser beam, and a carbonized layer of the coating mixture is formed on a surface of a recess formed at the irradiation position. Is generated and left to appear, and an apparent black marking is made.

[0006]

In the laser marking method according to the first aspect of the present invention, when the surface of the plastic work is irradiated with the laser beam, the plastic portion at the irradiated portion is heated and vaporized to form a concave portion, and the plastic surface is formed on the concave portion. The black carbonized layer of is generated and remains, and this carbonized layer becomes an apparent black marking.

In the laser marking method according to the second aspect, when the work surface coated with the mixture of the plastic fine particles and the coating material is irradiated with laser light, a part of the mixture coating film in the irradiation position in the thickness direction, or All of the thickness direction and part of the work are heated to vaporize and form a recess, and a black carbonized layer of plastic is generated and remains on the surface of the recess, and this carbonized layer appears to be a black marking. Become.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a laser marking method according to the present invention will be described below with reference to the drawings.
FIG. 1 is a sectional view of an irradiation portion of the first embodiment. In FIG. 1, the work 10 is made of plastic, and the concave portion formed on the surface of the work 10 corresponds to a portion where the portion irradiated with the laser light is heated and vaporized. In addition, a plastic black carbonized layer 11 is formed and remains on the surface of the recess, and the carbonized layer 11 becomes an apparent black marking.

2A and 2B are sectional views of the irradiation portion of the second embodiment. FIG. 2A is a sectional view when the recess is relatively shallow, and FIG. 2B is a sectional view when the recess is relatively deep. In Figure 2 (a),
The work 20 is made of a metal material, and a mixture 30 of fine plastic particles and paint is applied to the surface of the work 20. The relatively shallow concave portion formed on a part of the surface of the mixture 30 in the thickness direction corresponds to a portion where the portion irradiated with the laser light is heated and vaporized. Moreover, the mixture 30 is formed on the surface of the recess.
A black carbonized layer 31 of the plastic contained in is generated and remains, and this carbonized layer 31 becomes an apparently black marking.

In FIG. 2 (b), the work 20 is made of a metal material, and the surface of the work 20 is coated with the mixture 30 of fine plastic particles and paint, as in FIG. 2 (a). When the surface is irradiated with laser light, the entire irradiation portion of the mixture 30 in the thickness direction and a part of the work 20 are heated and vaporized to form a relatively deep recess. Moreover, the black carbonized layer 31 of plastic contained in the mixture 30 is generated and remains on the surface of the recess, and the carbonized layer 31
Is an apparent black marking.

In each of the first and second embodiments, the carbonized layers 11 and 31 apparently become clear black markings, and the carbonized layers 11 and 31 adhere firmly to the recessed surface. Therefore, it does not fade over time. Further, even if the surface of the work is rubbed with another member, the carbonized layers 11 and 31 are in the recessed portions from the surface of the work, and therefore there is no fear of disappearing. By the way, in the first embodiment, the color of the base material of the work 10 is the same except for the black marking portion. On the other hand, in the second embodiment, except for the black marking portion, the mixture 3
Since it is the color of the paint that constitutes 0, there is a feature that a desired color can be freely selected in terms of design.

Next, an apparatus for marking the surface of a work by irradiation with laser light will be described with reference to the block diagram of the marking apparatus common to the first and second embodiments of FIG. In FIG. 3, the laser light emitted from the laser oscillator 1 for the YAG laser is reflected by each deflection mirror 2
U and 2v oscillate at right angles to each other and irradiate the surface of the work 10 through the fθ lens 3. That is, the irradiation spot of the laser light is scanned on the surface of the work 10 by the respective deflection mirrors 2u and 2v, and the portion of this scanning locus is shallowly engraved and marked by the thermal action of the laser light. The fθ lens 3 is a special condensing lens, which deflects the laser light, which is oscillated by the deflection mirrors 2u and 2v and enters at a relatively large incident angle, to a position corresponding to the incident angle and focuses the laser light.

Each deflection mirror 2u, 2v is directly connected to each corresponding actuator 5u, 5v. This each actuator
The positions (rotation angles) of 5u and 5v are controlled by the control unit 6. The rotation axis of the deflection mirror 2u is an axis that passes through the central portion and is perpendicular to the paper surface. The rotation axis of the deflection mirror 2v is a central axis included in the mirror surface and parallel to the paper surface. Therefore,
The laser beam is swung in the X-axis direction on the surface of the work 10 by the rotation of the deflection mirror 2u, and the Y-axis (perpendicular to the paper surface) on the surface of the work 10 by the rotation of the deflection mirror 2v.
Will be shaken in the direction.

[0014]

According to the laser marking method of the first aspect, when the plastic work surface is irradiated with laser light, the plastic part at the irradiation location is heated to vaporize and form a concave portion, and the surface of the concave portion. A black carbonized layer of plastic is generated and remains on the surface. Further, in the laser marking method according to claim 2, when the surface of the work coated with the mixture of the plastic fine particles and the coating material is irradiated with the laser light, a part or a thickness of the mixture coating film at the irradiation position is irradiated. All of the depth direction and a part of the work are heated to vaporize and form a recess, and a black carbonized layer of plastic is formed and remains on the surface of the recess.

As a result, in any of the methods of claim 1 and claim 2, the carbonized layer apparently becomes a clear black marking. Moreover, since the carbonized layer is firmly adhered to the surface of the recess, it does not thin with time. Further, even if the surface of the work is rubbed with another member, the carbonized layer is in a recessed portion from the surface of the work, so that it does not disappear. In the method according to claim 1, the color of the base material of the plastic work is the color except for the black marking portion. On the other hand, in the method according to the second aspect, the color other than the black marking portion is the color of the paint constituting the mixture, and therefore, there is an effect that a desired color can be freely selected in terms of design.

[Brief description of drawings]

FIG. 1 is a sectional view of an irradiation portion of a first embodiment.

2A and 2B are cross-sectional views of the irradiation portion of the second embodiment, in which FIG. 2A is a sectional view when the recess is relatively shallow, and FIG. 2B is a sectional view when the recess is relatively deep.

FIG. 3 is a configuration diagram of a marking device common to the first and second embodiments.

[Explanation of symbols]

 1 Laser Oscillator 2u, 2v Deflection Mirror 3 fθ Lens 5u, 5v Actuator 6 Control Unit 10 Work 11 Carbonized Layer 20 Work 30 Mixture 31 Carbonized Layer

Claims (2)

[Claims] 1. A surface of a plastic work is irradiated with a laser beam, and a carbonized layer of plastic is generated and left on the surface of a recess formed at the irradiated position to perform apparent black marking. Laser marking method. 2. A surface of a work coated with a mixture of fine plastic particles and a coating material is irradiated with laser light, and a carbonized layer of the coating mixture is formed on the surface of a recess formed at the irradiation position.
A marking method using a laser, which is characterized in that the marking is made to remain and marking is apparently black.